Dr. Elise Riley is an Associate Professor in the Department of Medicine at the University of California, San Francisco. Trained as an epidemiologist, she has co-mentored 17 junior investigators and developed a longstanding multidisciplinary research program focused on HIV, drug use, health status and the use of health services in very low-income populations. She is currently funded by NIDA to conduct a homeless women's health study regarding the influences of HIV and polydrug use on cardiac injury. Here she proposes an expansion of the parent study to include two new biomarker outcomes, which will provide a better understanding of cardiac dysfunction through the consideration of multiple physiological pathways. Within this expanded body of research, Dr. Riley further proposes the concurrent augmentation of her mentoring activities for early career clinicians and trainees. The proposed activities leverage existing infrastructure, data and collaborations provided by Dr. Riley's current program, as well as additional NIH and UCSF resources. Collectively they will provide multiple opportunities for career development, a strong mentoring program for patient-oriented researchers and new projects that focus on understanding co-occurring exposures and health conditions to better inform health care delivery in highly vulnerable populations.